Unified error messages when being unable to convert to specific types using OnXXX helpers

activity.go

@@ -3,7 +3,7 @@ package activitypub
 import (
 	"bytes"
 	"encoding/gob"
-	"errors"
+	"fmt"
 	"reflect"
 	"strings"
 	"time"
@@ -758,7 +758,7 @@ func ToActivity(it Item) (*Activity, error) {
 			}
 		}
 	}
-	return nil, errors.New("unable to convert activity")
+	return nil, fmt.Errorf("unable to convert %T to activity", it)
 }
 
 // MarshalJSON encodes the receiver object to a JSON document.

collection.go

@@ -3,7 +3,7 @@ package activitypub
 import (
 	"bytes"
 	"encoding/gob"
-	"errors"
+	"fmt"
 	"reflect"
 	"time"
 	"unsafe"
@@ -336,7 +336,7 @@ func ToCollection(it Item) (*Collection, error) {
 			}
 		}
 	}
-	return nil, errors.New("unable to convert to collection")
+	return nil, fmt.Errorf("unable to convert %T to collection", it)
 }
 
 // FollowingNew initializes a new Following

collection_page.go

@@ -3,7 +3,7 @@ package activitypub
 import (
 	"bytes"
 	"encoding/gob"
-	"errors"
+	"fmt"
 	"reflect"
 	"time"
 
@@ -340,7 +340,7 @@ func ToCollectionPage(it Item) (*CollectionPage, error) {
 			}
 		}
 	}
-	return nil, errors.New("unable to convert to collection page")
+	return nil, fmt.Errorf("unable to convert %T to collection page", it)
 }
 
 // ItemsMatch

collection_page_test.go

@@ -138,7 +138,7 @@ func TestCollectionPage_Count(t *testing.T) {
 }
 
 func TestToCollectionPage(t *testing.T) {
-	err := fmt.Errorf("unable to convert to collection page")
+	err := func(it Item) error { return fmt.Errorf("unable to convert %T to collection page", it) }
 	tests := map[string]struct {
 		it      Item
 		want    *CollectionPage
@@ -152,17 +152,17 @@ func TestToCollectionPage(t *testing.T) {
 		"OrderedCollectionPage": {
 			it:      new(OrderedCollectionPage),
 			want:    new(CollectionPage),
-			wantErr: err,
+			wantErr: err(new(OrderedCollectionPage)),
 		},
 		"OrderedCollection": {
 			it:      new(OrderedCollection),
 			want:    new(CollectionPage),
-			wantErr: err,
+			wantErr: err(new(OrderedCollection)),
 		},
 		"Collection": {
 			it:      new(Collection),
 			want:    new(CollectionPage),
-			wantErr: err,
+			wantErr: err(new(Collection)),
 		},
 	}
 	for name, tt := range tests {

collection_test.go

@@ -188,7 +188,7 @@ func TestCollection_ItemMatches(t *testing.T) {
 }
 
 func TestToCollection(t *testing.T) {
-	err := fmt.Errorf("unable to convert to collection")
+	err := func(it Item) error { return fmt.Errorf("unable to convert %T to collection", it) }
 	tests := map[string]struct {
 		it      Item
 		want    *Collection
@@ -207,12 +207,12 @@ func TestToCollection(t *testing.T) {
 		"OrderedCollectionPage": {
 			it:      new(OrderedCollectionPage),
 			want:    new(Collection),
-			wantErr: err,
+			wantErr: err(new(OrderedCollectionPage)),
 		},
 		"OrderedCollection": {
 			it:      new(OrderedCollection),
 			want:    new(Collection),
-			wantErr: err,
+			wantErr: err(new(OrderedCollection)),
 		},
 	}
 	for name, tt := range tests {

intransitive_activity.go

@@ -3,7 +3,7 @@ package activitypub
 import (
 	"bytes"
 	"encoding/gob"
-	"errors"
+	"fmt"
 	"reflect"
 	"time"
 	"unsafe"
@@ -279,7 +279,7 @@ func ToIntransitiveActivity(it Item) (*IntransitiveActivity, error) {
 			}
 		}
 	}
-	return nil, errors.New("unable to convert to intransitive activity")
+	return nil, fmt.Errorf("unable to convert %T to intransitive activity", it)
 }
 
 // ArriveNew initializes an Arrive activity

object.go

@@ -502,7 +502,7 @@ func ToObject(it Item) (*Object, error) {
 			}
 		}
 	}
-	return nil, fmt.Errorf("unable to convert %q", it.GetType())
+	return nil, fmt.Errorf("unable to convert %T", it)
 }
 
 // Source is intended to convey some sort of source from which the content markup was derived,

ordered_collection.go

@@ -3,7 +3,7 @@ package activitypub
 import (
 	"bytes"
 	"encoding/gob"
-	"errors"
+	"fmt"
 	"reflect"
 	"time"
 	"unsafe"
@@ -342,7 +342,7 @@ func ToOrderedCollection(it Item) (*OrderedCollection, error) {
 			}
 		}
 	}
-	return nil, errors.New("unable to convert to ordered collection")
+	return nil, fmt.Errorf("unable to convert %T to ordered collection", it)
 }
 
 func copyOrderedCollectionToPage(c *OrderedCollection, p *OrderedCollectionPage) error {

ordered_collection_page.go

@@ -3,7 +3,7 @@ package activitypub
 import (
 	"bytes"
 	"encoding/gob"
-	"errors"
+	"fmt"
 	"reflect"
 	"time"
 
@@ -297,7 +297,7 @@ func ToOrderedCollectionPage(it Item) (*OrderedCollectionPage, error) {
 			}
 		}
 	}
-	return nil, errors.New("unable to convert to ordered collection page")
+	return nil, fmt.Errorf("unable to convert %T to ordered collection page", it)
 }
 
 // ItemsMatch

ordered_collection_page_test.go

@@ -117,7 +117,7 @@ func TestOrderedCollectionPage_Contains(t *testing.T) {
 }
 
 func TestToOrderedCollectionPage(t *testing.T) {
-	err := fmt.Errorf("unable to convert to ordered collection page")
+	err := func(it Item) error { return fmt.Errorf("unable to convert %T to ordered collection page", it) }
 	tests := map[string]struct {
 		it      Item
 		want    *OrderedCollectionPage
@@ -131,17 +131,17 @@ func TestToOrderedCollectionPage(t *testing.T) {
 		"OrderedCollection": {
 			it:      new(OrderedCollection),
 			want:    new(OrderedCollectionPage),
-			wantErr: err,
+			wantErr: err(new(OrderedCollection)),
 		},
 		"Collection": {
 			it:      new(Collection),
 			want:    new(OrderedCollectionPage),
-			wantErr: err,
+			wantErr: err(new(Collection)),
 		},
 		"CollectionPage": {
 			it:      new(CollectionPage),
 			want:    new(OrderedCollectionPage),
-			wantErr: err,
+			wantErr: err(new(CollectionPage)),
 		},
 	}
 	for name, tt := range tests {

ordered_collection_test.go

@@ -214,7 +214,7 @@ func TestOnOrderedCollection(t *testing.T) {
 }
 
 func TestToOrderedCollection(t *testing.T) {
-	err := fmt.Errorf("unable to convert to ordered collection")
+	err := func(it Item) error { return fmt.Errorf("unable to convert %T to ordered collection", it) }
 	tests := map[string]struct {
 		it      Item
 		want    *OrderedCollection
@@ -233,12 +233,12 @@ func TestToOrderedCollection(t *testing.T) {
 		"Collection": {
 			it:      new(Collection),
 			want:    new(OrderedCollection),
-			wantErr: err,
+			wantErr: err(new(Collection)),
 		},
 		"CollectionPage": {
 			it:      new(CollectionPage),
 			want:    new(OrderedCollection),
-			wantErr: err,
+			wantErr: err(new(CollectionPage)),
 		},
 	}
 	for name, tt := range tests {

place.go

@@ -275,7 +275,7 @@ func ToPlace(it Item) (*Place, error) {
 			}
 		}
 	}
-	return nil, fmt.Errorf("unable to convert %q", it.GetType())
+	return nil, fmt.Errorf("unable to convert %T to place", it)
 }
 
 type withPlaceFn func(*Place) error

profile.go

@@ -243,7 +243,7 @@ func ToProfile(it Item) (*Profile, error) {
 			}
 		}
 	}
-	return nil, fmt.Errorf("unable to convert %q", it.GetType())
+	return nil, fmt.Errorf("unable to convert %T to profile", it)
 }
 
 type withProfileFn func(*Profile) error

question.go

@@ -3,7 +3,7 @@ package activitypub
 import (
 	"bytes"
 	"encoding/gob"
-	"errors"
+	"fmt"
 	"reflect"
 	"time"
 
@@ -252,5 +252,5 @@ func ToQuestion(it Item) (*Question, error) {
 			}
 		}
 	}
-	return nil, errors.New("unable to convert to Question activity")
+	return nil, fmt.Errorf("unable to convert %T to question", it)
 }

relationship.go

@@ -258,7 +258,7 @@ func ToRelationship(it Item) (*Relationship, error) {
 			return i, nil
 		}
 	}
-	return nil, fmt.Errorf("unable to convert %q", it.GetType())
+	return nil, fmt.Errorf("unable to convert %T to relationship", it)
 }
 
 type withRelationshipFn func(*Relationship) error

tombstone.go

@@ -249,7 +249,7 @@ func ToTombstone(it Item) (*Tombstone, error) {
 			}
 		}
 	}
-	return nil, fmt.Errorf("unable to convert %q", it.GetType())
+	return nil, fmt.Errorf("unable to convert %T to tombstone", it)
 }
 
 type withTombstoneFn func(*Tombstone) error